Two Phase 3 Results Announced for Eliglustat Tartrate for Gaucher Disease

Genzyme announced new data from the Phase 3, ENGAGE and ENCORE studies of eliglustat tartrate, an investigational oral therapy for Gaucher disease type 1. Eliglustat tartrate, a novel glucosylceramide analog given orally, is designed to partially inhibit the enzyme glucosylceramide synthase resulting in reduced production of glucosylceramide. Glucosylceramide is the substance that builds up in the cells and tissues of people with Gaucher disease.

ENGAGE was a randomized, double-blind, placebo-controlled study designed to evaluate the safety and efficacy of eliglustat tartrate in 40 treatment-naïve patients with Gaucher disease type 1. The primary efficacy endpoint was improvement in spleen size in patients treated with eliglustat tartrate. ENCORE was a multi-national, randomized, controlled, open-label, study designed to determine whether eliglustat tartrate is non-inferior to Cerezyme (imiglucerase for inj.; Genzyme). In the trial 160 patients with Gaucher disease type 1 who had begun enzyme replacement therapy at least three years prior to randomization and who had reached therapeutic goals were randomized (2:1) to receive either eliglustat tartrate or Cerezyme for one year. The primary efficacy endpoint of stability was a composite endpoint of pre-specified change criteria for spleen volume, hemoglobin levels, platelet counts, and liver volume. To meet the endpoint for stability, a patient had to remain stable in all four parameters.

The ENGAGE study met its primary endpoint with a statistically significant improvement in spleen size at nine months in patients treated with eliglustat tartrate compared to placebo. Spleen volume in patients treated with eliglustat tartrate decreased from baseline by a mean of 28% compared with a mean increase of 2% in placebo patients, for an absolute difference of 30% (P<0.0001). The ENCORE study also met its primacy efficacy endpoint with a majority of patients in both groups remaining stable one year after randomization (84% of eliglustat tartrate patients and 94% of Cerezyme patients). In an additional, pre-specified, efficacy analysis of the percent change in spleen volume from baseline, a mean change of -6% was observed in the eliglustat tartrate arm compared with -3% in the Cerezyme arm. This analysis also met the criteria for non-inferiority.